1. Field of the Invention
The present invention relates generally to liquid level gauges and more specifically to a liquid level gauge in combination with a vessel.
2. Description of the Prior Art
In the field of household appliances, certain liquid reservoirs have included a sight glass liquid gauge which overlies a relatively large opening in the side of the liquid reservoir to conveniently show the amount of liquid contained therein. In many of these gauges, the opening is equivalent to the height of the expected water level to be observed. Using such an extended opening increases the surface area which must be sealed between the sight glass and the vessel wall, thus reducing the reliability of the seal and decreasing the life of the appliance.
Commercial appliances, for example large coffee urns, have used an external column communicating with the reservoir by at least one (if not two) pipe connections which are physically separated from the vessel. This type of liquid level gauge has been found satisfactory in the commercial market, yet has not been satisfactorily incorporated into smaller household appliances. The reason for this lack of incorporation of the principle into the smaller appliances is the expense involved in the connection between the column and the body of the reservoir. Similarly, household appliances are generally made of thin walled steel and thus are not capable of being threaded so as to receive the pipe connection between the reservoir and the liquid level column. Also, in household appliances, the use of an external column physically separated from the vessel provides an object which is easily broken in every-day ordinary use.
Thus, there exists a need in the small appliance area (specifically, coffee percolators, coffee urns, steam irons, etc.) for an efficient and long-lasting liquid level gauge. Since the gauges are generally extra features for the convenience of the consumer and do not necessarily vary the specific function of the household appliance, the expense of the appliance should not be unduly increased by the type of gauge used. Thus, the gauge to be incorporated into this smaller appliance must be economical in the number of parts used and in its process of assembly.